Oxime silane based crosslinkers are used for producing neutral moisture-curing silicone sealants. Using these silane compounds, hydroxy-functionalized silicone polymers are crosslinked to obtain a silicone elastomer under the effect of a catalyst and moisture. When using oximino crosslinkers, no acetic acid or amine is released in contrast to acid or alkaline crosslinking systems, but 2-butanone oxime. As this cleavage product reacts neutrally, sealing compounds based on oximino crosslinkers can be used even on sensitive substrates such as marble.
Since in Europe MEKO releasing sealants are under a lot of pressure, probably in 2017 MEKO releasing sealants will be banned from the European market for a big part. As a solution, now we are producing Acetoxime & Methyl Isobutyl Ketoxime based crosslinkers, like our PC7131, PC7133, PC7530, PC7531 etc.
The various Crosslinker differ by their reactivity, with the general rule being: TOS > VOS > MOS.
Mixing different Crosslinker types enables setting the rate of a formulation precisely, i. e. skin-over time, curing rate and time to first elastic recovery.
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